The present invention relates to a dot matrix printer of the impact type and, more particularly, to dot matrix elements employed in a dot matrix printer.
Generally, there are two types of dot matrix printers, namely, the impact type and the non-impact type. Examples of the impact type dot matrix printer are the cross point dot printer and the wire type dot printer. The non-impact type dot matrix printer is also well known in the art, for example, the electric discharge type dot printer and the ink jet system printer.
The impact type dot matrix printer is widely used, but the mechanical portion thereof is complicated and is often damaged during operation. The electric discharge type dot printer requires a chemically treated print receiving paper and generates harmful gas during operation. The ink jet system printer requires a complicated control circuit and is expensive.
Accordingly, an object of the present invention is to provide a dot matrix printer of the impact type of a simple construction.
Another object of the present invention is to provide a dot matrix printer of the impact type which ensures stable operation.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a plurality of magnetic dot elements are aligned in a matrix fashion, each of the magnetic dot elements comprising a cylindrical magnet and a conical impact member fixed to the cylindrical magnet. The magnetic dot elements are supported by a supporter in the printer in such a manner that the magnetic dot elements are rotatable and can shift their positions along their axes.
A magnetic field control means including a plurality of horizontal line conductors and a plurality of vertical line conductors is provided, each cross point of the horizontal line conductors and the vertical line conductors being positioned above the respective magnetic dot elements. The horizontal line conductors and the vertical line conductors are connected to control circuits, respectively, in order to control the orientation of each of the magnetic dot elements in accordance with print information. The magnetic field control means functions to rotate the magnetic dot elements so that the conical impact member of a selected magnetic dot element faces a print receiving member.
A depression plate is associated with the magnetic dot elements to depress the magnetic dot elements toward the print receiving member in such a manner that the conical impact members of the selected magnetic dot elements come into contact with the print receiving member with the intervention of an ink ribbon, whereby a desired character is printed on the print receiving member in a dot matrix fashion.